Catalyst for the production of ammonia and process of making the same.



rear oath.

FREDRIK W. DE J'AHN, OF NEW YORK. N. Y., ASSIGNOR TO GENERAL CHEMICAL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

CATALYST FOR THE PRODUCTION OF AMMONIA AND PROCESS OF MAKING THE SAME.

No Drawing. Original application filed July 8. 1914, Serial No. 849,680. Divided Specification of Letters Patent.

Patented Nov. 9, 1915.

and this application filed May 5, 1915. Serial No. 25,902.

T 0 all whom it may concern:

Be it known that I, FREDRIK W. DE JAHN a subject of the King of Norway, and a residcnt of the borough of Manhattan, city, county, and State of New York, have 1nvented certain new and useful Improvements in Catalysts for the Production of Ammonia and Processes of Making the Same, of which the following is a speclfication.

My invention relates to the synthetic production of ammonia and more particularly to a new catalytic agent therefor, its production and use.

The present application is a division of my application, which has become Patent 1,141,948, dated June 8, 1915.

I have discovered that if a gaseous mixture containing nitrogen and hydrogen is suitably passed in contact with a suitable material composed essentially of (1) nitrogen, (2) an alkali metal such as sodium or potassium. and (3) one or more of the following metals, all of which are for the purpose of this invention equivalents z manganese, cobalt, cerium, boron, titanium,uranium and silicon, the nitrogen and hydrogen of the gaseous mixture are united to form ammonia. v

In order that my invention may be clearly understood, it is now set forth in the form of specific examples, it being understood, of course, that the invention is not to be limited to the exact materials or proportions thereof nor to the temperature or other conditions of the examples, since these/may be varied without departing from my invention. 1 J

It is also to be understood that a catalyzer may contain either manganese, cobalt, icerium, boron, titanium, uranium or' silicon, together with an alkali metal and nitrogen," or may contain two or more of these, metals together with an alkali metal and nitrog'en; in the latter case the percentage of the alkali metal plus nitrogen in [the catalyzer' is preferably not varied, that isto 'say' for; example, if instead of cobalt in the catalyzer it is desired to substitute cobalt and "tita j nium, the proportion of the 'c'obaltandtitm, nium combined, to the alkalimetal' and nitrogen combined, is substantiallythe sameas' the proportion of cobalt to the alkali metal and nitrogen combined, in the original c'ata lyzer, while the ratio of the cobalt to the titanium may be any ratio desired. In a like manner, part or all of the particular alkali metal mentioned, say sodium, may be replaced by another alkali metal, as for instance, potassium. Moreover, the manganese, cobalt, cerium, boron, titanium, uranium and silicon, whether said metals are usedin the catalyzer singly or in associated relation, may be replacedin part by iron, nickel, and molybdenum, which last mentloned metals are more specifically referred to and claimed in my Patent 1,141,947, dated June 8, 1915, the present invention being in the nature of an improvement over the invention of said patent.

Example I-Preparing the catalytic materiaZ.-Pumice stone in small pieces is purified by treatment with hydrochloric acid for about twenty-four (24:) hours; it is then washed with distilled water until free from chlorid and then ignited to dryness.

A. Of this product 100 grams are treated with substantially the atomic weight in grams (59 grams) of cobalt in the form of nitrate dissolved in the necessary quantity of water, say 150 grams of water, and the whole is evaporated to dryness, being stirred thoroughly during the evaporation; in this way the cobalt is to be uniformly distributed over the pumice. The thus treated pumice is now ignited at about 550 C. until fumes are no longer given off and is then heated at about the same temperature in an atmosphere of hydrogen until water is no longer formed. To this product, when cooled in an indifferent atmosphere such as hydrogen and while still in such atmosphere, add 69 grams of 'metallic sodium (or 117 grams of metallic potassium) in small pieces and then heat the Whole for the purpose of melting the sodium and distribute the molten sodium over the surface of the pumice material as, forexample, by suitable continued stirring; displace the indiflerent gas by anhydrous ammonia vapor or gas and heat the material to about 300 C. while passing ammonia vapor until a practically constant weight is obtained. Preserve the material, after being cooled,'ready for use in, for example, a dry atmosphere of ammonia.

]B In place of the atomic weight in grams of cobalt in the form of nitrate in the foregoing Example A, I can use the atomic weight in grams of manganese or titanium, preferably in the form of chlorid.

C. In place of the hydrogen used in treating the ignited pumice and cobalt or the like material, I can use a, mixture of nitrogen and hydrogen or other suitable reducing gas.

D. In the case of the elements cerium, uranium and silicon, I have found it ad- Y in the form of chlorid with 69 grams of metallic sodium, or 28 grams of silicon in the form of chlorid with 92 grams of metallic sodium, or 238 grams of uranium in the form of chlorid with 92 grams of metallic sodium. (In place of the sodium I may use the equivalent amount of metallic potassium). Heat the result of such treatment to about 300 C. until the further formation of sodium chlorid substantially ceases; then treat with hot distilled water until practically all the water-soluble chlorid has been removed; now wash well with distilled water and dry by gentle heating in an indifferent atmosphere such as hydrogen; now add in each case 69 grams of metallic sodium or theequivalent amount of metallic potassium; heat to a temperature just above the melting point of the sodium and distribute the molten sodium uniformly over the surface of the pumice material, as, for example, by suitable continued stirring. Now displace the hydrogen or other indifferent gas by means a of anhydrous ammonia vapor or gas and raise the temperature of the whole to 300 C. and maintain that condition until a practically constant weight is obtained; after cooling preserve the material ready foruse in a dry atmosphere of, for example, ammonia. E. In the caseof boron, I prefer to proceed as follows: I make a paste of the element in finely powdered condition (for example, in the so-called impalpable powder form) with water and thoroughly commingle this paste with the aforementioned prepared pumice while applying heat in sufficient and roper amount and rate to drive ofi substantlally all of the water; add to the result a quantity of metallic sodium amounting to 69 grams of metallic sodium for each atomic weight in grams of the boron employed, which has been ascertained to have been ailixed to the prepared pumice in each case. Take the (59 grams of metallic sodium or their proportionate weight determined as above, in finely divided condition, and heat the whole in an indifferent atmosphere such as hydrogen to just above the melting point of the sodium and distribute the molten sodium uniformly over the surface of the pumice material, as, for example, by continued stirring. Now displace the hydrogen or other indifferent gas by means of anhydrous ammonia vapor or gas and raise the temperature of the whole to 300 C. and maintain in that condition until a practically constant weight is obtained; after cooling preserve the material ready for use in, for example, a dry atmosphere of ammonia.

F. It is also useful to prepare catalysts containing more than one of the above named non-alkali elements. For instance, in Example A, I can use in place of the 59 grams of the element cobalt, 29.5 grams thereof and 24 grams of the element titanium, both in the form of chlorid. I can use the 69 grams of sodium or a portion thereof putting in the place of the omitted portion an equivalent amount of metallic potassium, or I may put in place of the 69 grams of metallic sodium 117 grams of metallic potassium;

In Example A, I can also use in place of the 59 grams of the element cobalt 16 grams each of the elements iron, cobalt and titanium, all in the form of chlorid. I can also suitably use combinations of the elements iron nickel and cobalt as mixed nitrates and chlorids as circumstances may indicate or make desirable.

The methods used in D or E above can also be applied to all the other elements if desired, but I prefer the 'methods above given for the respective elements recited. Sodium or potassium amid can be used and the pumice or other suitable carrier may be omitted.

By these methods or a suitable combination of all or part of them, it is possible to produce any desired combination of elements as catalysts.

Ewample IIUtz'lizz'ng the catalytic to produce amm0n-ia.For producing ammonia about 175 grams of the product of Example A above, or a corresponding amount of its equivalent, are placed in a suitable catalytic chamber for ammonia synthesis and there is passed in contact with such catalyzer a gas current preferably containing one volume of nitrogen for every three volumes of hydrogen. The gas mixture must be suitably purified and must be freed especially from contact poisons in the well known manner. With the pressure of the gas traversing the chamber within the range of 80 to 90 atmospheres and the temperature of treatment approximately bethe total gas leaving tween 520 C. and 540 0., I have succeeded in producing synthetic ammonia to the extent that the ammonia gas leaving the treating chamber constituted 4.5% by volume of such chamber. The ammonia is removed from the gas discharged from the catalytic chamber in any suitable manner.

Wherever in this specification or in the claims annexed thereto I have used the word cobalt, I mean, of course, to include therein'each and all of the aforementioned equivalents thereof, either alone or in mixture with each other; likewise when in this specification or in the claims thereto annexed I have used the Word sodium, I mean to include in that term the equivalent thereofdisclosed herein, namely, potassium. Moreover, when in the claims I specify broadly or specifically in the making of the catalyzer that (A) cobalt.(or its equivalent) is added to (B) an alkali metal, and the product thus formed is treated with (C) a gas containing nitrogen, I mean to include also the equivalents of such process, among which equivalents I mention the addition of (A) cobalt to the product resulting from the treatment of the metal (B) with the gas (C) the addition of the metal (B) to an oxid or suitable salt of the metal (A) followed by the reduction of the compound of the metal (A) as by hydrogen, the resulting product being then treated with the gas (C); and

the'addition of a suitable compound, such as an amid, of the metal (B) to the metal (A).

I claim:

' 1. As a new article of manufacture, a

substance containing cobalt, sodium and nitrogen, and which can cause nitrogen and hydrogen to combine to produce ammonia.

2. The herein described process of making a catalytic agent suitable for producing ammonia, which consists in adding (1) cobalt to (2) sodium and treating the product so formed with a basic gas containing nitrogen.

3. The herein described process of making a catalyticagent suitable for producing ammonia, which consists in adding (1) cobalt to (2) sodium and treating the product so formed with ammonia.

4. The herein described process of making a catalytic agent suitable for producing ammonia, which consists in treating a compound of cobalt with metallic sodium, removing water soluble material from the product. formed, then treating the result with metallic sodium and finally treating the resultant product with ammonia.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

FREDRIK W. DE JAHN. Witnesses:

JOHN A. FERGUSON, FRITZ ZIEGLER, Jr. 

